Project Summary/Abstract The goal of the ECHO Consortium is to identify exposures and mechanisms that link the environment in early life to childhood development and health outcomes. This proposal commits to the ECHO Consortium numerous resources from the Extremely Low Gestation Age Newborn (ELGAN) Study. Since its initiation in 2001, the broad goal of the ELGAN Study is to evaluate the relationship between perinatal inflammation and neurodevelopmental impairments among individuals born extremely premature (i.e., before 28 weeks of gestation). In the proposed project we will build on the success of the ELGAN Study by adding new information about: 1) environment exposures, 2) neurodevelopmental outcomes of study participants at 15 and 18 years of age, and 3) placental epigenetic variation, a mechanism that could link inflammation early in life to neurodevelopmental impairments. In the first two years of the project (the UG3 phase) investigators from the ELGAN team will participate in the design of studies that can be implemented across the ECHO Consortium and in efforts to harmonize data across cohorts comprising the consortium. In the second year of the proposal, we will begin to evaluate members of the ELGAN cohort, as they reach 15 years of age, using standardized neurodevelopmental assessments and brain magnetic resonance imaging (MRI). We also will complete preliminary studies of relationships between prenatal environmental exposures, early life inflammation, and neurodevelopmental impairments, using extant data from the ELGAN cohort. In addition, we will complete analysis of epigenetic markers in placenta specimens collected around the time of the births of ELGAN Study participants. These data will be utilized in the last 5 years of the proposed project (the UH3 phase). If pre-specified milestones are met, the project will transition into the UH3 phase. Standardized neurodevelopmental assessments and brain magnetic resonance imaging (MRI) will be completed as study participants reach 15 years. As participants reach 18 years of age neurodevelopmental assessments will again be completed. At the assessment at 18 years we will obtain blood for study of epigenetic markers of activation of innate immunity, which we can then relate to our extant data about systemic inflammation early in life. Specific aims in the UH3 phase of the project are examine relationships between biomarkers of early life inflammation (extant data on neonatal systemic inflammation and new data on placenta epigenetics) and neurodevelopmental impairments through age 18 years. The over-arching hypothesis to be addressed is that prenatal exposures can initiate early life inflammation, thus increasing the risk of neurodevelopmental impairments. Innovative aspects of this project include its longitudinal perspective, consideration of placenta epigenetics as a mechanism linking prenatal exposures to childhood outcomes, and evaluation of a wide range of neurodevelopmental outcome. This research has the potential to inform the development of therapies targeting epigenetic processes to prevent or ameliorate cognitive disability, thereby improving the quality of life for 16,000 individuals who survive extremely premature birth each year in the United States.